138 CARBONIFEROUS AMMONOIDS OF AMERICA. 



stage, of Graham, Young County, Tex., associated with Gastrioceras (jJo- 

 hulosmn Meek and Worthen, (i. suhcavum Miller and Gurley, Schistoceras 

 hUdrethi Morton, 8. hyatti Smith, Gonioloboceras ivelleri Smith, Dhnorphoceras 

 texanum Smith, Agathiceras ciscoense Smith, Schuchertites grahaml Smith, 

 Popmioceras ganti Smith, and a typical braehiopod and pelecypod Coal 

 Measures fauna. The beds in which these fossils were obtained lie about 

 a tliousand feet below the Wichita Permian beds. This is a remarkable 

 assemblage of ammonites to be found below the Permian, but it will be 

 noted, by reference to the plates accompanying this paper, tliat they are all 

 primitive or transitional forms, such as one would expect to find in the 

 Upper Coal Measures. 



The type figured on PI. Ill, figs. 11-13, was collected by the writer in 

 the Cisco beds on Salt Creek, in the outskirts of Graham, Tex. Dimen- 

 sions of the type : 



Milimeter. 



Diameter, about 38 



Height of last whorl 1-1 



Height of last whorl from the preceding 7 



Width of last whorl 26 



Involution 24 



Width of uml)iUeus 14 



The type is in the collection of the writer, deposited in the geologic 

 collection of Leland Stanford Junior University, California. 



In the U. S. National Museum are tlu-ee specimens (two of 27203 and 

 one of 27201), which were also used in preparing the diagnosis of the genus 

 and species, and in illustrating the development of the septa. 



The specific name is given in honor of Prof Y. W. Simonds, of Austin, 



Tex. 



Genus Waagenocekas Gemmellaro. 



This is the most complex of American Paleozoic ammonoids, and the 

 only one that in the strictest sense may be said to have developed entirely 

 bevond the limits of the goniatites and to have become a true ammonite in 

 all its characters. 



All known species of this genus have a compact Arcestes-Vike shajje, 

 with rounded whorl and moderately narrow mnbilicus. The septa are com- 

 plex, amraonitic and phylloid, the lobes and saddles numerous, and all 

 digitate. The internal divisions are almost as numerous as the external, in 

 this respect strongly resembling Arcestes. 



